Re: [PATCH v12 2/5] soc: qcom: Add Sleep stats driver

Shawn Guo
2021-10-19T09:24:21Z

Hi Maulik,

On Wed, Oct 13, 2021 at 12:08:21PM +0530, Maulik Shah wrote:
> From: Mahesh Sivasubramanian <msivasub@codeaurora.org>
>
> Let's add a driver to read the stats from remote processor and
> export to debugfs.
>
> The driver creates "qcom_sleep_stats" directory in debugfs and
> adds files for various low power mode available. Below is sample
> output with command
>
> cat /sys/kernel/debug/qcom_sleep_stats/ddr
> count = 0
> Last Entered At = 0
> Last Exited At = 0
> Accumulated Duration = 0
>
> Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
> Signed-off-by: Lina Iyer <ilina@codeaurora.org>
> [mkshah: add subsystem sleep stats, create one file for each stat]
> Signed-off-by: Maulik Shah <mkshah@codeaurora.org>
> ---
> drivers/soc/qcom/Kconfig | 10 ++
> drivers/soc/qcom/Makefile | 1 +
> drivers/soc/qcom/qcom_stats.c | 277 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 288 insertions(+)
> create mode 100644 drivers/soc/qcom/qcom_stats.c
>
> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> index abfef20..3cf3a6b 100644
> --- a/drivers/soc/qcom/Kconfig
> +++ b/drivers/soc/qcom/Kconfig
> @@ -199,6 +199,16 @@ config QCOM_SPM
> to manage cores, L2 low power modes and to configure the internal
> Adaptive Voltage Scaler parameters, where supported.
>
> +config QCOM_STATS
> + tristate "Qualcomm Technologies, Inc. (QTI) Sleep stats driver"
> + depends on (ARCH_QCOM && DEBUG_FS) || COMPILE_TEST
> + depends on QCOM_SMEM
> + help
> + Qualcomm Technologies, Inc. (QTI) Sleep stats driver to read
> + the shared memory exported by the remote processor related to
> + various SoC level low power modes statistics and export to debugfs
> + interface.
> +
> config QCOM_WCNSS_CTRL
> tristate "Qualcomm WCNSS control driver"
> depends on ARCH_QCOM || COMPILE_TEST
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index 24514c7..70d5de6 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -21,6 +21,7 @@ obj-$(CONFIG_QCOM_SMP2P) += smp2p.o
> obj-$(CONFIG_QCOM_SMSM) += smsm.o
> obj-$(CONFIG_QCOM_SOCINFO) += socinfo.o
> obj-$(CONFIG_QCOM_SPM) += spm.o
> +obj-$(CONFIG_QCOM_STATS) += qcom_stats.o
> obj-$(CONFIG_QCOM_WCNSS_CTRL) += wcnss_ctrl.o
> obj-$(CONFIG_QCOM_APR) += apr.o
> obj-$(CONFIG_QCOM_LLCC) += llcc-qcom.o
> diff --git a/drivers/soc/qcom/qcom_stats.c b/drivers/soc/qcom/qcom_stats.c
> new file mode 100644
> index 0000000..817505b
> --- /dev/null
> +++ b/drivers/soc/qcom/qcom_stats.c
> @@ -0,0 +1,277 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2011-2021, The Linux Foundation. All rights reserved.
> + */
> +
> +#include <linux/debugfs.h>
> +#include <linux/device.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/seq_file.h>
> +
> +#include <linux/soc/qcom/smem.h>
> +#include <clocksource/arm_arch_timer.h>
> +
> +#define RPM_DYNAMIC_ADDR 0x14
> +#define RPM_DYNAMIC_ADDR_MASK 0xFFFF
> +
> +#define STAT_TYPE_OFFSET 0x0
> +#define COUNT_OFFSET 0x4
> +#define LAST_ENTERED_AT_OFFSET 0x8
> +#define LAST_EXITED_AT_OFFSET 0x10
> +#define ACCUMULATED_OFFSET 0x18
> +#define CLIENT_VOTES_OFFSET 0x1c

From downstream 'struct msm_rpm_stats_data' [1], it looks that
CLIENT_VOTES_OFFSET should be 0x20?

Shawn

[1] https://source.codeaurora.org/quic/la/kernel/msm-4.19/tree/drivers/soc/qcom/rpm_stats.c?h=kernel.lnx.4.19.r17-rel#n46

> +
> +struct subsystem_data {
> + const char *name;
> + u32 smem_item;
> + u32 pid;
> +};
> +
> +static const struct subsystem_data subsystems[] = {
> + { "modem", 605, 1 },
> + { "wpss", 605, 13 },
> + { "adsp", 606, 2 },
> + { "cdsp", 607, 5 },
> + { "slpi", 608, 3 },
> + { "gpu", 609, 0 },
> + { "display", 610, 0 },
> + { "adsp_island", 613, 2 },
> + { "slpi_island", 613, 3 },
> +};
> +
> +struct stats_config {
> + size_t stats_offset;
> + size_t num_records;
> + bool appended_stats_avail;
> + bool dynamic_offset;
> + bool subsystem_stats_in_smem;
> +};
> +
> +struct stats_data {
> + bool appended_stats_avail;
> + void __iomem *base;
> +};
> +
> +struct sleep_stats {
> + u32 stat_type;
> + u32 count;
> + u64 last_entered_at;
> + u64 last_exited_at;
> + u64 accumulated;
> +};
> +
> +struct appended_stats {
> + u32 client_votes;
> + u32 reserved[3];
> +};
> +
> +static void qcom_print_stats(struct seq_file *s, const struct sleep_stats *stat)
> +{
> + u64 accumulated = stat->accumulated;
> + /*
> + * If a subsystem is in sleep when reading the sleep stats adjust
> + * the accumulated sleep duration to show actual sleep time.
> + */
> + if (stat->last_entered_at > stat->last_exited_at)
> + accumulated += arch_timer_read_counter() - stat->last_entered_at;
> +
> + seq_printf(s, "Count: %u\n", stat->count);
> + seq_printf(s, "Last Entered At: %llu\n", stat->last_entered_at);
> + seq_printf(s, "Last Exited At: %llu\n", stat->last_exited_at);
> + seq_printf(s, "Accumulated Duration: %llu\n", accumulated);
> +}
> +
> +static int qcom_subsystem_sleep_stats_show(struct seq_file *s, void *unused)
> +{
> + struct subsystem_data *subsystem = s->private;
> + struct sleep_stats *stat;
> +
> + /* Items are allocated lazily, so lookup pointer each time */
> + stat = qcom_smem_get(subsystem->pid, subsystem->smem_item, NULL);
> + if (IS_ERR(stat))
> + return -EIO;
> +
> + qcom_print_stats(s, stat);
> +
> + return 0;
> +}
> +
> +static int qcom_soc_sleep_stats_show(struct seq_file *s, void *unused)
> +{
> + struct stats_data *d = s->private;
> + void __iomem *reg = d->base;
> + struct sleep_stats stat;
> +
> + memcpy_fromio(&stat, reg, sizeof(stat));
> + qcom_print_stats(s, &stat);
> +
> + if (d->appended_stats_avail) {
> + struct appended_stats votes;
> +
> + memcpy_fromio(&votes, reg + CLIENT_VOTES_OFFSET, sizeof(votes));
> + seq_printf(s, "Client Votes: %#x\n", votes.client_votes);
> + }
> +
> + return 0;
> +}
> +
> +DEFINE_SHOW_ATTRIBUTE(qcom_soc_sleep_stats);
> +DEFINE_SHOW_ATTRIBUTE(qcom_subsystem_sleep_stats);
> +
> +static void qcom_create_soc_sleep_stat_files(struct dentry *root, void __iomem *reg,
> + struct stats_data *d,
> + const struct stats_config *config)
> +{
> + char stat_type[sizeof(u32) + 1] = {0};
> + size_t stats_offset = config->stats_offset;
> + u32 offset = 0, type;
> + int i, j;
> +
> + /*
> + * On RPM targets, stats offset location is dynamic and changes from target
> + * to target and sometimes from build to build for same target.
> + *
> + * In such cases the dynamic address is present at 0x14 offset from base
> + * address in devicetree. The last 16bits indicates the stats_offset.
> + */
> + if (config->dynamic_offset) {
> + stats_offset = readl(reg + RPM_DYNAMIC_ADDR);
> + stats_offset &= RPM_DYNAMIC_ADDR_MASK;
> + }
> +
> + for (i = 0; i < config->num_records; i++) {
> + d[i].base = reg + offset + stats_offset;
> +
> + /*
> + * Read the low power mode name and create debugfs file for it.
> + * The names read could be of below,
> + * (may change depending on low power mode supported).
> + * For rpmh-sleep-stats: "aosd", "cxsd" and "ddr".
> + * For rpm-sleep-stats: "vmin" and "vlow".
> + */
> + type = readl(d[i].base);
> + for (j = 0; j < sizeof(u32); j++) {
> + stat_type[j] = type & 0xff;
> + type = type >> 8;
> + }
> + strim(stat_type);
> + debugfs_create_file(stat_type, 0400, root, &d[i],
> + &qcom_soc_sleep_stats_fops);
> +
> + offset += sizeof(struct sleep_stats);
> + if (d[i].appended_stats_avail)
> + offset += sizeof(struct appended_stats);
> + }
> +}
> +
> +static void qcom_create_subsystem_stat_files(struct dentry *root,
> + const struct stats_config *config)
> +{
> + const struct sleep_stats *stat;
> + int i;
> +
> + if (!config->subsystem_stats_in_smem)
> + return;
> +
> + for (i = 0; i < ARRAY_SIZE(subsystems); i++) {
> + stat = qcom_smem_get(subsystems[i].pid, subsystems[i].smem_item, NULL);
> + if (IS_ERR(stat))
> + continue;
> +
> + debugfs_create_file(subsystems[i].name, 0400, root, (void *)&subsystems[i],
> + &qcom_subsystem_sleep_stats_fops);
> + }
> +}
> +
> +static int qcom_stats_probe(struct platform_device *pdev)
> +{
> + void __iomem *reg;
> + struct dentry *root;
> + const struct stats_config *config;
> + struct stats_data *d;
> + int i;
> +
> + config = device_get_match_data(&pdev->dev);
> + if (!config)
> + return -ENODEV;
> +
> + reg = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
> + if (IS_ERR(reg))
> + return -ENOMEM;
> +
> + d = devm_kcalloc(&pdev->dev, config->num_records,
> + sizeof(*d), GFP_KERNEL);
> + if (!d)
> + return -ENOMEM;
> +
> + for (i = 0; i < config->num_records; i++)
> + d[i].appended_stats_avail = config->appended_stats_avail;
> +
> + root = debugfs_create_dir("qcom_stats", NULL);
> +
> + qcom_create_subsystem_stat_files(root, config);
> + qcom_create_soc_sleep_stat_files(root, reg, d, config);
> +
> + platform_set_drvdata(pdev, root);
> +
> + return 0;
> +}
> +
> +static int qcom_stats_remove(struct platform_device *pdev)
> +{
> + struct dentry *root = platform_get_drvdata(pdev);
> +
> + debugfs_remove_recursive(root);
> +
> + return 0;
> +}
> +
> +static const struct stats_config rpm_data = {
> + .stats_offset = 0,
> + .num_records = 2,
> + .appended_stats_avail = true,
> + .dynamic_offset = true,
> + .subsystem_stats_in_smem = false,
> +};
> +
> +static const struct stats_config rpmh_data = {
> + .stats_offset = 0x48,
> + .num_records = 3,
> + .appended_stats_avail = false,
> + .dynamic_offset = false,
> + .subsystem_stats_in_smem = true,
> +};
> +
> +static const struct of_device_id qcom_stats_table[] = {
> + { .compatible = "qcom,rpm-stats", .data = &rpm_data },
> + { .compatible = "qcom,rpmh-stats", .data = &rpmh_data },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, qcom_stats_table);
> +
> +static struct platform_driver qcom_stats = {
> + .probe = qcom_stats_probe,
> + .remove = qcom_stats_remove,
> + .driver = {
> + .name = "qcom_stats",
> + .of_match_table = qcom_stats_table,
> + },
> +};
> +
> +static int __init qcom_stats_init(void)
> +{
> + return platform_driver_register(&qcom_stats);
> +}
> +late_initcall(qcom_stats_init);
> +
> +static void __exit qcom_stats_exit(void)
> +{
> + platform_driver_unregister(&qcom_stats);
> +}
> +module_exit(qcom_stats_exit)
> +
> +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. (QTI) Stats driver");
> +MODULE_LICENSE("GPL v2");
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
>